/f 


-   rOR'r 


Issued  March  .">,  1900. 


U.S.  DEPARTMENT   OF  AGRICULTURE, 

BUREAU  OF  PLANT  [ND1  STRY     Circular  No.  24. 
B.    I    GALLOWAY.  Chief  of  Bureau. 


ALFALFA   IX   CULTIVATED   HOWS  roll  SEED 
PRODUCTION  IN  SEMIARID  REGIONS. 


CHARLES  .1.  BRAND,  Physiologist, 

AND 

J.  M.  WESTGATE,  Agronomist, 
Bureai    of  Plant  [ndt  go  bi  . 


WASHINGTON  :  GOVERNMENT  PRINTINQ  OFFICE  :   1909 


BUREAU  OF  PLANT  INDUSTRY. 

Physiologist  and  Pathologist,  and  chief  of  Bureau,  Beverly  T.  Galloway. 

Physiologist  and  Pathologist,  mid  Assistant   chief  of   Bureau,  Albert  F.   Woods. 

Laboratory  of  Plant  Pathology,  Erwin  F.  Smith,  Pathologist  in  Charm'. 

Fruit  Disease  Investigations,  Morton  B.  Waite,  Pathologist  in  Charge. 

Investigations  in  Fdrest  Pathology,  Haven  Metcalf,  Pathologist  in  Charge. 

Cotton   and   Truck   Diseases   and   Plant   Disease  Survey,   William   A.   Orton,   Pathologist   in 
Charge. 

Pathological  Collections  and  Inspection    Work,  Flora  W.  Patterson,  Mycologisl   in  charge. 

Plant  Life  History  Investigations,  Walter  T.   Swingle,   Physiologist  in  Charge. 

Cotton   Breeding   Investigations,  Archibald  D.   Sharael   and   Daniel  N.   Shoemaker.   Physi- 
ologists in  Charge. 

Tobacco    Investigations,    Archibald    D.    Shamel,    Wightman    W.    Garner,    and    Ernest    II. 
Mathewson,   in   Charge. 

Corn  Investigations,  Charles  P.  Hartley,  Physiologist  in  Charge. 

Alkali  and  Drought  Resistant  Plant  Breeding  Investigations,  Thomas  II.  Kearney,  Physi- 
ologist   in   Charge. 

Soil   Bacteriology   and   Water  Purification    Investigations,    Karl    F.   Kellerman,    Physiolo- 
gist in  Charge. 

Bionomic  Investigations  of  Tropical  and  Subtropical   Plants,  Orator  F.  Cook.  Bionomisi 
in  Charge. 

Drug  and  Poisonous  Plant  and   Tea  culture  Investigations,  Rodney  II.  True.   Physiologist 
in  Charge. 

Physical  Laboratory,  Lyman  J.  Briggs,  Physicist  in  Charge. 

Agricultural  Technology,  Nathan  A.  Cobb,   Crop  Technologist    in  Charge. 

Taxonomic  and  Range  Investigations,  Frederick  V.  Coville,  Botanist  in  Charge. 

Farm  Management,  William  .1.  Spillman,  Agriculturist   in  Charge. 

drain  Investigations,  Mark  Alfred  Carleton,  Cerealist  in  Charge. 

Arlington    Experimental  Farm   and   Horticultural   Investigations,   Lee   C.   Corbett,    Horti 
culturist  in  Charge. 

Vegetable  Testing  Gardens,  William  W.  Tracy,  sr..   Superintendent. 

Sugar-Beet  Investigations,  Charles   0.   Townsend,    Pathologist    in   Charge. 

Western   Agricultural  Extension,  Carl  s.   Scofteld,   Agriculturist    in   Charge 

Dry-Land  Agriculture  Investigations,  E.  Charming  Chilcott.  Agriculturist  in  Charge. 

Pomological  Collections,  Gustavus  B.  Brackett,   Pomologisl   in  Charge. 

Field  Investigations  in  Pomology,  William  A.  Taylor  and  G.   Harold  Powell,   Pomologists 
in  Charge. 

Experimental  Gardens  and  Grounds,  Edward  M.  Byrnes,  Superintendent. 

Foreign  Seed  and  Plant  Introduction.  David   Fairchild.   Agricultural    Explorer   in  Charge. 

Forage  Crop  Investigations.  Charles   V.    Piper,    Agrostologist    is   Charge. 

Seed  Laboratory,   Edgar   Brown, . Botanist    in   Charge. 

Grain  Standardization,  John  D.  Shanahan,  Crop  Technologist  in  Charge. 

Subtropical  Garden,  Miami.  Fla.,  P.  J.  Wester,  in  Charge 

Plant   Introduction  Garden,  Chico,  Cat,  W.  W.  Tracy,  jr..  Assistant  Botanist   in  Charge. 

South  Texas  Garden,  Brownsville,  Tex.,  Edward  C   (Jreen,  Pomologisl  In  Charge. 

Farmers'  Cooperativt   Demonstration    Work,  Seaman  A.  Knapp.  Special    i-genl   iii  Charge 

Seed   Distribution    (Directed   by   Chief  of   Bureau),    Lisle  Morrison.   Assistant    in   General 
Charge. 


Editor,  J.  E.  Rockwell. 

Chief   Clerk,   James   E.    Jones. 


[Cir.  24] 

9 


B.  P.   I 


ALFALFA  l\  CI  LTIVATED  ROWS  FOR  SEED  PRO- 
DUCTION IN  SEMIARID  REGIONS. 


INTRODUCTION. 

The  growing  of  alfalfa  in  cultivated  rows  for  seed  is  of  more 
recent  origin  in  this  country  than  is  the  production  of  hay  l>v  this 
method.  John  Spurrier,  in  a  book  entitled  "The  Practical  Farmer," 
published  at  Wilmington,  Del.,  in  L793,  appears  to  be  the  firs!  Amer- 
ican writer  to  mention  the  growing  of  alfalfa  in  cultivated  rows. 
The  cultivation  was  designed  to  retard  the  development  of  weeds, 
which  often  prove  verj  destructive  to  broadcasted  seedings  of  a  I  fa  I  fa 
in  the  Middle  and  South  Atlantic  States.  This  method  is  -till  prac- 
ticed to  a  slight  extent  iii  a  few  places  in  the  South,  where,  however. 
the  climate  is  too  humid  for  the  successful  production  of  alfalfa 
seed. 

-in  observations  made  during  the  summer  of  1906  by  investigators  in  this 
Bureau,  including  the  present  authors,  ii  became  apparent  that  the  margin 
between  success  and  failure  in  profitable  alfalfa  growing  in  regions  of  light 
rainfall  is  often  so  narrow,  even  when  the  most  drought-resistant  strains  are 
used,  as  to  be  determined  almost  wholly  by  the  methods  of  cultivation  em- 
ployed. Experiments  were  inaugurated  to  lest  1 1 1  * »  value  of  various  methods 
"i  seeding  alfalfa,  including  thai  of  sowing  ii  in  rows  properly  spaced  to  per- 
inii  ..f  intertillage. 

The  results  obtained  in  these  preliminary  experiments  and  those  secured  by 
practical  farmers  in  the  semiarid  sections  on  a  Held  scale  indicate  clearly  thai 
increased  yields  of  seed  will  follow  the  use  of  this  method.  The  value  of  row 
seeding  and  cultivation  in  hay  production  is  also  being  investigated.  The  area 
seeded  to  alfalfa  is  increasing  so  rapidly  thai  it  is  not  possible  to  secure 
enougb  home-grown  seed  to  supply  the  demand.  As  a  result,  several  million 
(-  of  foreign  seed  of  various  grades,  bul  often  of  rather  inferior  quality, 
are  imported  annually. 

Ii  is  believed  thai  the  developmeul  of  seed  production  in  cultivated  rows  will 
go  far  toward  meeting  the  home  demand  with  a  domestic  supply  and  thai  at 
the  same  time  a  considerable  advance  in  the  development  of  the  semiarid  sec- 
tions of  the  country  where  farming  operations  are  handicapped  by  lack  of 
moisture  will  he  brought  about,  for  these  reasons  it  is  thoughl  advisable  to 
make  the  details  of  this  method,  so  far  as  they  have  been  developed,  available  to 

ih..-.'   now    c lucting    farming    operations    in    those    regions   of    lighl    rainfall 

where  the  method  promises  to  give  the  host  result-,  l'..  T.  Galloway,  Phys- 
iologist mill  Pathologist,  and  Chief  'if  Bureau, 

[Cir.24] 

3 


4  ALFALFA    IN    CULTIVATED    ROWS   FOR   SEED. 

In  England  as  early  as  1730,  Jethro  Tull,  the  inventor  of  the  drill 
and  the  originator  of  tillage  of  farm  crops  in  the  modern  sense, 
advocated  and  practiced  the  growing  of  alfalfa  (lucern)  in  rows. 
His  teachings  first  appeared  in  his  "  Specimens.'1  Later,  in  1829, 
these  were  republished  by  Cobbett  in  a  work  entitled  "  Tull's  Horse- 
Hoeing  Husbandry." 

What  was  apparently  the  first  attempt  to  grow  alfalfa  for  seed 
in  cultivated  rows  in  this  country  was  made  by  what  was  then  known 
as  the  Section  of  Seed  and  Plant  Introduction  of  the  United  States 
Department  of  Agriculture.  Several  contract  fields  of  Turkestan 
alfalfa  were  seeded  in  wide  rows  in  different  parts  of  the  Great 
Plains  area  in  L903.  The  poor  seeding  habits  of  Turkestan  alfalfa 
when  grown  in  this  country,  together  with  the  fact  that  the  plants 
were  grown  much  too  thickly  in  the  rows,  greatly  handicapped  the 
logical  development  of  this  method. 

The  application  of  the  row  method  of  cultivation  has  been  suggested 
by  a  number  of  American  experimenters,  including  Prof.  W.  J. 
Spillman,"  Prof.  W.  M.  Hays,6  Prof.  W.  A.  Wheeler.'  Mr.  W.  M. 
Jardine,'7  and  Mr.  C.  S.  Scofield.c  Of  these  only  Professor  Wheeler 
has  used  the  method  on  an  experimental  and  field  scale  and  his 
results  arc  confirmatory  to  those  presented  in  this  paper. 

The  work  on  which  the  conclusions  here  presented  are  based  has 
been  conducted  at  various  experiment  farms  of  this  Bureau  and  on 
the  farms  of  Mr.  Lewis  Brott,  Sextorp,  Nebr. ;  Mr.  E.  Bartholomew, 
Stockton,  and  Dr.  W.  A.  Workman,  Ashland.  Ivans. 

Bow  cultivation  for  seed  growing  has  been  in  use  for  a  number  of 
years  in  the  vineyard  regions  of  southern  Germany,  particularly  in 
Baden  and  Bavaria,  in  the  production  of  seed  of  Alt-Deutsche  Friink- 
ische  luzerne,  a  well-recognized  German  strain.  It  is  said  that  alfalfa 
i-  grown  in  cultivated  rows  for  seed  in  parts  of  Russia,  where  hand 
cultivators  prove  an  effective  and  practical  means  of  holding  the 
weeds  in  check  and  of  conserving  soil  moisture. 

The  method  has  been  employed  for  a  number  of  years  by  Dr.  L. 
Trabut,   government    botanist    of    Algeria.     Fairchild  '    describes   a 

"  Annual  Report  for  1903  of  Minnesota  State  Agricultural  Society.     1904. 

h  Ilanly  Alfalfa  in  Minnesota.  Press  Bulletin  No.  20,  University  Experiment 
Station,  Minnesota.     1904. 

c  Forage  1'lanis  at  the  Highmore  Substation,  1906.  Bulletin  No.  mi.  South 
Dakota  Agricultural  Experiment   Station.     1907. 

''Arid  Farming  Investigations.  Bulletin  No.  100,  Utah  Agricultural  Experi- 
ment  Station.      1906.      i  Issued  in   1907.) 

"Dry  Farming  in  the  Ureal  Basin.  Bulletin  No.  103,  Bureau  of  Plant  In- 
dustry, U.  s.  Department  of  Agriculture.     iui>7. 

'  Fairchild,  David.  Cultivation  of  Wheat  in  Permanent  Alfalfa  Fields.  Bul- 
letin No.  72,  part  1,  Bureau  of  Plant  Industry.  U.  S.  Department  of  Agriculture. 
1904. 

[Cir.  24] 


ALFALFA    IN    CULTIVATED    ROWS    FOB    SEED.  5 

method  of  growing  wheal  between  alfalfa  rows  in  Algeria  under 
light  rainfall,  where  ii  has  been  found  possible  to  produce  a  crop  oli 
wheal  between  the  wide  rows  of  alfalfa  in  alternate  years.  The 
practical  value  of  this  method  for  the  semiarid  portions  of  the  United 
States  was  indicated  in  the  publication  mentioned,  without,  however, 
making  any  direcl  reference  to  the  seed-producing  possibilities  of 
alfalfa  -own  in  cultivated  row-  under  such  conditions. 

PRINCIPLES   UNDERLYING   ALFALFA  SEED   PRODUCTION. 

Although  alfalfa  has  been  grown  increasingly  in  the  West  since 
L854  or  lv-">-"'  little  has  been  done  to  develop  a  rational  -red  industry. 
Ii  is  a  matter  of  common  observation  that  even  in  recognized 
producing  sections  the  seed  crop  is  very  uncertain.  A  study  of  some 
of  the  factors  that  cause  success  or  failure  has  indicated  some  of  the 
underlying  principles  affecting  the  production  of  profitable  seed 
crops.  En  Bulletin  118  of  this  Bureau  "  at  lent  ion  was  directed  to  the 
fact  that  cultivated  alfalfa  is  not  a  homogeneous  species,  but  is  com- 
posed of  numerous  races,  -trains,  varieties,  and  even  subspecies. 
These  vary  greatly  in  many  characters,  and  especially  in  their  seed 
producing  capacity,  no  pure  varieties  of  known  high  value  comparable 
with  those  we  have  of  corn,  wheat,  and  other  crops  having  as  yet  been 
established.  It  has  also  been  noted  that  the  individuals  constituting 
these  diverse  races,  elementary  species,  or  whatever  they  may  be 
called,  exhibit  great  variation  among  themselves.  This  is  partial 
larly  true  of  their  ability  to  set  seed.  To  overcome  the  source  of 
error  resulting  from  this  diversity  in  individual  plant:-  the  method 
of  vegetative  propagation  described  by  Westgate  and  Oliver,6  of  the 
Bureau  of  Plant  Industry,  has  been  used  in  a  portion  of  this  work. 

It  ha-  often  been  noted  that  a-  a  rule  i-olated  alfalfa  plant-  set 
seed  far  more  profusely  than  those  in  all  bul  the  thinnest  stands. 
Observations  on  this  point  have  been  made  in  various  parts  of  the 
(iivat  Plains  and  intermountain  area-  and  in  the  farther  Southwest. 
On  the  Arlington  Experimental  Farm,  near  Washington,  I).  ('..  an 
experiment  was  performed  t<»  determine  the  effect  of  different  de 
grees  of  isolation  on  the  seed-setting  ability  of  alfalfa.  In  this 
experiment,  cuttings  from  a  heavj  seeding  plant  were  rooted  in  the 
greenhouse  and  later  set  out  at  varying  interval.-.  Inasmuch  a-  these 
plant-  were  propagated  vegetativelj  from  the  same  mother  plant. 
the\    did   not   -how    the   individual   variation  •mentioned   above  that 


•Brand,  Charles  .1.  Peruvian  Alfalfa:  A  New  Long-Season  Variety  for  the 
Southwest.  Bulletin  No.  its.  Bureau  of  Plant  industry,  I".  s.  Departnienl  of 
Agriculture.     1907. 

'The  Application  of  Vegetative  Propagation   to  Leguminous  Forage  Plants. 
Bulletin  No.  102,  part   I.  Bureau  "i  Plant   [ndustry,  U.  s.  Departmenl  of  Agri- 
culture.    1907. 
[Or.  imj 


6  ALFALFA   IN    CULTIVATED   ROWS   FOR  SEED. 

would  have  entered   into  the  experiment  had  seedling  plants  been 
utilized. 

The  plants  occupying  a  space  equivalent  to  a  7-inch  square  pro- 
duced a  maximum  of  38  pods,  while  those  having  at  their  command 
a  space  equal  to  an  11-inch  square  produced  a  maximum  of  96  pods. 
The  highest  number  of  pods  formed  on  plants  grown  in  rows  39 
inches  apart  and  18  inches  apart  in  the  rows  was  505. 

It  will  be  noted  that  the  yields  were  in  almost  direct  proportion 
to  the  areas  occupied.  However,  it  was  evident  that  the  plants  hav- 
ing the  greatest  distance  between  them  had  not  utilized  fully  their 
allotted  space.  This  was  accounted  for  by  the  fact  that  it  was  their 
hist  season's  growth.  An  adjoining  two-year-old  cutting  from 
another  plant  of  similar  seed-producing  tendencies  produced  2,080 
pods,  and  this  without  utilizing  all  of  the  space  of  18  inches  in  the 
39-inch  row  assigned  to  it.  Although  part  of  this  difference  may 
have  been  due  to  inherent  capacity,  the  chief  explanation  for  it  must 
be  sought  in  the  firm  establishment  of  the  plant  and  its  greater 
maturity. 

Just  why  the  isolation  of  plants  increases  the  production  of  seed 
has  not  been  fully  determined,  but  it  is  apparent  that  one  of  the 
factors  involved  is  the  increased  amount  of  sunlight  available  to  the 
plant.  It  has  often  been  observed  that  trees  grown  on  the  banks 
of  irrigation  ditches  in  alfalfa  fields  or  along  the  margins  of  fields 
always  interfere  with  normal  seed  production  as  far  as  the  influence 
of  their  shade  extends.  In  the  course  of  an  experiment  on  the  seed 
setting  of  alfalfa  it  was  found  that  partial  shading  materially  re- 
duced the  quantity  of  seed  produced  by  plants  not  already  receiving 
more  than  the  optimum  amount  of  sunlight. 

When  alfalfa  plants  have  sufficient  space  for  full  development 
they  have  approximately  equal  illumination  on  ail  sides.  The  effect 
of  this  is  well  shown  in  figure  1.  In  this  case  seed  has  developed 
over  the  entire  plant  and  not  at  the  top  only,  as  is  the  case  in  thick 
stands,  where  there  is  more  or  less  competition  for  the  requisite 
amount  of  light  and  air.  With  the  plants  so  far  apart  that  when 
fully  developed  they  barely  occupy  the  ground  the  potential  seed 
producing  surface  exposed  on  an  acre  is  nearly  double  that  of  a  thick 
stand.  In  the  latter,  because  of  crowding,  the  plants  are  unable  to 
produce  seed,  apparently  on  account  of  shading  by  closely  associated 
individuals.  „ 

In  addition  to  the  injurious  influence  of  shade,  the  crowding  of 
plants  interferes  with  seed  production  by  depriving  Hie  plants  of 
sufficient  moisture  to  enable  them  to  mature  their  seed  properly. 
This,  of  course,  is  true  only  in  areas  of  light  rainfall.  On  the  other 
hand,  in  sections  where  irrigation  is  practiced  thick'  stands  l>\  check- 
ing evaporation  bring  about  such  moist   conditions  in   lields  as  to 

[Cir.  24] 


ALFALFA  IN  CULTIVATED  ROWS  FOB  SEED.  7 

promote  unfavorable  conditions  and  so  prevent  maximum  yields  of 
seed. 
The  basal  shoots  which  usually  appear  when  the  plant  begins  to 

i'l are  developed  at  the  expense  of  the  seed  crop.     The  energy 

that  should  be  devoted  solely  to  the  maturing  of  the  seed  is  diverted 
by  tlii-  new  growth.     Perhaps  the  mosl  important  factor  influencing 


I  ?%&*%& 


Ucuvilj  seeded  Isolated  alfalfa  plant  grown  near  Washington,  D.  C,  where  the 
clmatlc  conditions  are  much  more  unfavorable  to  the  production  of  alfalfa  seed  than  in 
the  semiarid  sections, 

the  development  of  these  basal  shoots  which  are  to  form  the  succeed- 
ing crop  is  the  wain-  contenl  of  the  soil.  If  the  moisture  supply  be 
ample,  the  basal  shoots  commence  their  growth  about  the  time  the 
plant  comes  into  bloom.  This  is  disastrous  to  the  seed  crop,  and  for 
this  reason  it  is  necessary  thai  there  be  a  sufficient  shortage  of  tnois- 

[Clr.24] 


8  ALFALFA    IN    CULTIVATED    ROWS   FOR   SEED. 

ture  at  this  time  to  retard  or  prevent  altogether  the  development  of 
these  shoots.  In  the  seed-producing  sections  of  the  more  humid  parts 
of  the  Great  Plains  area  profitable  crops  of  alfalfa  seed  are  usually 
obtained  only  in  the  occasional  seasons  of  drought  so  extreme  that 
the  yield  of  other  crops  is  greatly  reduced. 

Drought  is  used  here  in  a  qualified  sense.  There  must,  of  course, 
be  enough  moisture  in  the  soil  to  enable  the  seed  to  mature  fully ; 
otherwise  it  will  be  deficient  in  germinating  power.  On  the  other 
hand,  the  soil  must  not  contain  enough  moisture  to  force  into  growth 
the  crown  buds  that  produce  the  succeeding  crop. 

The  favorable  conditions  for  the  production  of  alfalfa  seed  which 
prevail  in  the  semiarid  regions  are  due  principally  to  the  presence 
there  of  a  favorable  adjustment  of  the  supply  of  moisture  in  the  soil 
to  the  moisture  requirements  of  the  plant  when  grown  for  seed.  This 
is  especially  true  when  the  plants  are  grown  in  cultivated  rows,  as 
the  moist  ure  content  of  the  soil  can  then  be  regulated  to  some  degree 
by  proper  cultivation. 

THE  RELATION  OF  INSECTS  TO  THE  SETTING  OF  ALFALFA  SEED. 

Insect  visits  are  essential  to  the  proper  pollination  of  the  alfalfa 
flower.  If  fertile  seed  is  to  be  produced  in  any  quantity  it  is  neces- 
sary that  a  certain  explosive  mechanism  within  the  flower"  be  re- 
leased. The  release  of  this  mechanism,  whether  it  be  accomplished 
by  insects  or  otherwise,  is  popularly  called  "  tripping." 

Experiments  and  observations  h  both  by  the  writers  and  by  other  in- 
vestigators indicate  that  practically  no  seed  is  produced  if  the  flowers 
are  not  tripped.  Bumblebees  (Bombus  spp.)  are  generally  believed 
to  he  the  most  efficient  of  all  insects  in  setting  off  the  explosive  mech- 
anism, and  hence  in  bringing  about  pollination.  Honeybees,  though 
not  nearly  so  effective  as  bumblebees,  should  not  be  underrated  in  this 
connection.  It  is  a  practice  in  somef parts  of  the  country  to  place 
beehives  along  the  margins  of  alfalfa  fields  intended  for  seed.  Bee 
keepers  follow  with  their  colonies  fields  planted  for  seed,  for  the 

"  By  Hie  explosion  of  an  alfalfa  flower  is  meanl  (he  snapping  out  of  the 
stamens  and  pistil  from  the  wings  and  keel,  which  had  hitherto  enveloped 
them,  to  a  new  position  against  the  standard.  This  lakes  place  when  certain 
insect  visitors  insert  their  nectar-gathering  organs  into  the  flower.  The  un- 
pad of  Hie  stigma  and  stamens  againsl  \\\>-  body  of  the  insect  appears  to  have 
a i  leasl  three  immediate  and  important  results:  i  l  »  The  wounding  of  the  stig- 
matic  surface  of  the  pistil,  making  it  more  susceptible  to  fertilization:  ti'i  the 
contact  of  I  his  sensitive  surface  with  pollen  home  on  the  insect's  hody  from 
previously  visited  flowers;  and  (3)  the  dusting  of  new  pollen  on  the  insect 
which  will  function  in  pollinating  (lowers  subsequently  visited. 

'■The  particular  Investigations  in  regard  to  the  relation  of  the  tripping  of  the 
alfalfa    flower   to   (he  setting  of  seed,   upon   which    (his   is  a    preliminary   report, 
have  been  conducted  principally  by  the  junior  author  of  this  publication. 
[CU-.  24] 


ALFALFA    IN    CULTIVATED  BOWS  FOB  SI  9 

purpose  of  getting  the  honey.  This  is  mutually  beneficial,  as  larger 
yield- of  both  seed  and  honey  result.  Wild  bees  (Andrena  spp.  and 
Megachile  spp.)  and  various  butterflies  are  also  valuable  agents  in 
pollinating  al  fal  fa  flowers. 

That  the  explosh f  al  fal  fa  flowers  may  be  accomplished  by  other 

mean-  than  insect  visitation  is  quite  well  known.  The  insertion  of  a 
more  or  less  pointed  instrument  into  the  throat  of  the  corolla  has 
often  been  resorted  to  in  studying  the  tripping  mechanism  of  indi- 
vidual flowers.  Roberts  and  Freeman"  describe  a  method  of  ex- 
ploding flowers  in  large  numbers  by  rolling  the  head  carefully  but 

firmly  between  the  il b  and  the  first  and  second  fingers.     This  trips 

the  flowers  then  at  the  proper  stage  of  maturity.  Tripping  on  a  still 
more  wholesale  scale  may  be  done  by  grasping  the  entire  plant  be- 
tween the  hand-  at  successive  intervals.  In  this  case  it  is  besl  to 
work  from  the  bottom  toward  the  top  of  the  plant,  exerting  the 
required  pressure  at  the  proper  intervals. 

It  has  been  found  that  flowers  tripped  by  any  form  of  manipula- 
tion set  seed  readily,  while  other  (lower-  left  unexploded  and  from 
which  insects  are  excluded  rarely  set  seed. 

A.s  only  a  slight  pressure  on  the  keel  is  necessary  to  trip  the  flower 
artificial  method-  may  be  resorted  to  as  a  mean-  of  supplementing  the 
natural  process  as  accomplished  by  insects.  In  an  experiment  at  the 
Arlington  Experimental  Farm  in  which  the  method  mentioned  of 
exerting  pressure  successively  over  the  whole  plant  was  used,  the  yield 
of  pod-  was  increased  25|  per  cent  over  adjoining  row-  not  thus 
treated.  At  Chico,  ( 'al..  an  increase  of  L29  per  cent  in  the  number  of 
pods  resulted.  Although  greater  seed  yields  also  result,  two  experi- 
ments at  least  indicate  that  the  increase  in  the  number  of  seeds  is  not 
in  as  high  proportion  as  is  the  increase  in  the  number  of  pods. 

Further  experiments  and  more  exact  observations  under  varying 
conditions  in  different  sections  will  be  necessary  to  determine  just 
when  sufficiently  increased  yields  of  seed  may  be  expected  to  justify 
the  expense  of  the  undertaking.  Any  alfalfa  seed  producer  ma\  test 
this  method  experimentally  on  a  small  scale. 

A  hundred  plants  may  be  counted  off  and  tripped  by  hand  three 
times  a  week  during  the  blooming  period,  using  either  of  the  methods 
previously  described.  Another  hundred  plants  of  similar  seeding 
habits  should  be  left  to  be  exploded  by  insects.  An\  greater  produc- 
tion of  seed  on  a  given  number  of  head-  on  the  manipulated  plants 
a-*  compared  with  the  same  number  of  heads  on  those  not  so  manip- 
ulated may  with  reasonable  safety  be  attributed  to  artificial  tripping. 

If  the  increased  yield-  which  have  been  obtained  in  the  prelimi- 
nary experiments  arc  equaled  in  ~<->-i\  producing  sections,  it   i-  | 

Bulletin  No.  151,  Kansas  Agricultural  Experiment  Statiou 

70451— <  ik.  -I     09       -2 


10 


ALFALFA  IX  CULTIVATED  ROWS  FOR  SEED. 


able  that  means  will  be  devised  for  exploding  the  flowers  on  a  large 
scale.  The  only  sections  in  which  this  method  will  be  likely  to  prove 
profitable  are  those  where  for  any  reason  proper  insects  are  not 
present  in  sufficient  numbers  to  explode  a  large  percentage  of  the 
HoAvers. 


AREAS  TO  WHICH   THE   GROWING   OF  ALFALFA  FOR  SEED   IN 
CULTIVATED  ROWS  IS  ADAPTED. 

The  experiments  thus  far  carried  out  in  the  production  of  seed 
in  cultivated  rows  have  been  located  principally  in  the  semiarid 
portions  of  the  Great  Plains,  in  the  intermountain  area,  and  in  the 
Palouse  country  of  eastern  Washington.     The  field  shown  in  figure  2 


Fig.  2.  Alfalfa  in  cultivated  rows  for  seed,  near  Stockton,  Kans.  In  the  more  mature 
rows  shown  at  the  right  and  left  the  first  crop  was  devoted  to  seed  production,  while 
in  the  rows  in  the  middle  of  the  illustration  later  growths  were  left  for  seed.  Photo- 
graphed July  i>,   1908. 

is  on  (he  farm  of  Mr.  E.  Bartholomew,  near  Stockton,  Ivans.  It  is 
probable  that  the  method  will  be  found  to  be  adapted  to  many  of  the 
semiarid  sections  of  the  country  which  have  a  rainfall  of  from  1  1  to 
l20  inches,  and  possibly  also  to  irrigated  sections  where  the  supply 
of  water  is  insufficient  for  the  production  of  full  hay  crops.  It  is 
also  recommended  lor  trial  in  irrigated  sections  having  water  for 
hut  half  or  less  of  the  normal  acreage  of  alfalfa  in  the  district, 
and  also  for  fields  lying  slightly  higher  than  the  ditch  lines  but 
which  have  the  water  level  moderately  near  the  surface. 

Experiments  in   humid   sections  indicate   that   even  there  row  cul- 
tivation   makes   possible   much   higher  yields   of   seed   than    are   pro- 
[Cir.24] 


\i.i  Ml  A    IN    «  II. I  l\  A  I  ED    ROM  S    FOB    SEED.  II 

(lured  by  fields  -own  broadcasl   or  drilled   in  the  ordinary  manner. 

Figure  1  -hew-  the  seed  production  of  an  individual  plant  at  the 
Arlington  Experimental  Farm,  where  the  average  rainfall  i-  \'-'>\ 
inches.  It  is  doubtful,  however,  whether  even  this  method  will 
insure  the  production  of  paying  crops  of  alfalfa  seed  under  humid 
condil  ion-. 

Row  cultivation  under  condition-  of  ample  rainfall  is  more  valuable 
a-  a  method  id'  weed  control  than  for  increasing  seed  yields.  At  the 
time  when  pud  formation  i-  going  on.  a  certain  amount  of  dry 
weather  and  heat  i-  necessary  to  insure  the  greatest  production  of 
alfalfa  seed,  even  w  hen  the  plants  arc  isolated.  This  method  promises 
to  lie  more  successful  in  sections  where  the  annual  rainfall  k  from 
1  !  in  -J"  inches  than  elsewhere.  Where  the  precipitation  ranges  from 
•jo  in  l'.">  inches  thin  seeding  by  broadcasting  or  drilling  in  the  ordi- 
nary way  may  be  preferable  to  row  cultivation.  Field-  -own  by 
either  of  these  method-  can  he  kept  up  at  much  less  expense.  Less 
frequent  cultivation  will  he  necessary,  and  when  needed  may  he  given 
with  an  alfalfa  renovator  or  a  disk,  straight-toothed,  or  slant-toothed 
harrow.  Under  these  method-,  as  in  row  cultivation,  the  stand  inn-; 
be  very  thin  if  the  best  results  are  to  he  obtained. 

SELECTION    OF   SOIL. 

In  the  semiarid  sections  the  ordinary  arable  land,  such  as  i-  used 
for  the  common  farm  crops,  will  prove  well  adapted  to  this  work  so 
far  a-  fertility  is  concerned.  Ina-nnich  as  the  child'  purpose  of  culti- 
vation   is    moisture    conservation,    -oil-    of    large    moisture-holding 

capacity  should  he  used  when  there  i-  opportunity  for  choice.  Care 
should  he  taken  t<i  avoid  held-  too  alkaline  for  ordinary  crops. 

LOCATION  OF  FIELDS. 

In  many  pari-  of  the  semiarid  sections  alfalfa  held-  are  located  in 
swale-  or  draws  or  on  creek  bottoms  where  the  moisture  conditions 
are  the  best  that  ate  available.  Where  the  rainfall  i-  very  light  it 
will  he  safest  to  utilize  such  places  for  growing  alfalfa  in  rows  for 
-ceil.  Where  the  precipitation  is  greater  or  the  run-off  which  the 
held  secures  from  the  surrounding  area  is  sufficient,  alfalfa  held-. 
for  either  -i^'d  or  hay.  may  he  sown  thinly  either  broadcast  or  with 
the  drill,  thus  obviating  a  large  pari  of  the  expense  of  cultivation. 
It  ma\  hi'  -ahl\  assumed  that  alfalfa  in  cultivated  row-  will  sui 
under  somewhat  drier  condition-  than  held-  grown  by  ordinary 
methods.  In  those  part-  of  the  semiarid  sections  where  the  rainfall 
i-  relatively  heavy  it  is  probable  that  even  the  highest  and  driesl 
portions  of  the  farm  maj  be  successfully  utilized  l>\  the  row  method. 

LCir.  _lj 


12  ALFALFA    IN    CULTIVATED   ROWS   FOR   SEED. 

PREPARATION  OF   THE  SEED  BED. 

The  preparation  of  the  ground  should  be  such  as  to  rid  it  as  far 
as'  possible  of  weeds  and  at  the  same  time  to  provide  a  seed  bed 
which  has  become  well  firmed  by  settling  or  rolling,  or  both.  In 
the  drier  portions  of  the  semiarid  regions  summer-fallowing  the 
preceding  season  may  be  necessary  to  provide  the  soil  with  the 
moisture  required  to  insure  prompt  germination  of  the  seed.  This 
implies  keeping  the  field  in  the  cleanest  possible  culture  during 
the  previous  summer.  Weeds  must  be  controlled  and  proper  tillage 
must  be  given  after  each  rain.  The  soil  mulch  thus  maintained  will 
check  evaporation  and  in  the  following  year  place  at  the  disposal 
of  the  young  plants  the  greater  part  of  two  years'  rainfall. 

In  the  North,  where  spring  planting  is  advisable,  surface  tillage 
must  be  continued  until  seeding  time.  In  many  cases  it  will  not 
be  necessary  to  summer-fallow  if  the  field  is  devoted  to  a  cultivated 
crop,  such  as  corn,  during  the  preceding  year. 

In  the  Great  Plains  country,  when  the  ground  is  plowed,  immediate 
harrowing  and  rolling  should  follow  the  plowing.  In  addition,  sub- 
surface packing  is  advised  for  all  spring-plowed  land,  hut  may 
often  be  omitted  in  the  case  of  fall  plowing,  as  natural  settling  sup- 
plemented by  harrowing  and  rolling  usually  produces  a  sufficiently 
firm  seed  bed.  If  firming  is  not  done  there  will  be  at  the  bottom 
of  the  new  furrow  a  dry,  porous  stratum  of  the  old  topsoil.  This 
condition,  which  is  present  in  all  freshly  plowed  fields  where  the 
Mil  face  is  dry,  may  result  fatally  to  the  young  alfalfa  plants,  as 
their  roots  can  not  make  the  necessary  development  in  this  layer, 
containing  dry  soil,  clods,  and  air  spaces.  If  the  field  is  not  to  be 
left  fallow  long  enough  for  harrowing  and  natural  settling  to 
make  the  ground  sufficiently  firm  below,  this  injurious  condition 
should  be  remedied  by  subsurface  packing  with  suitable  implements. 
It  is  necessary  that  there  be  sufficient  moisture  in  the  soil  at  seeding 
time  to  enable  the  jDlant  to  make  a  sufficiently  rapid  growth  to  permit 
of  surface  tillage  without  covering  up  the  young  plants. 

The  purpose  of  subsurface  packing  is  not  to  prevent  loss  of 
moisture,  bui  to  reestablish  the  capillary  column  which  was  inter- 
rupted by  the  plowing  under  of  the  dry  topsoil.  Unless  this  is  done 
the  moisture  from  the  lower  soil  can  not  reach  the  roots  of  the  plant. 
Immediate  harrowing  also  prevents  considerable  loss  of  moisture 
from  the  new  topsoil. 

In  regions  where  the  greater  part  of  the  annual  rainfall  comes 
during  the  winter  and  where  the  ground  does  not  freeze  to  a  great 
depth  or  remain  frozen  for  a  long  period,  as  is  the  case  in  a  large 
pari  of  the  intermountain  area  and  in  the  southern  part  of  the  Great 
Plains,  it   may  be  undesirable  to  level  and   linn   immediately  after 

[Clr.  24] 


\i  i  \u  \    i\    CULTIVATED    i;>>\\  S    FOB    SEED.  13 

plowing,  as  is  indicated  for  the  middle  and  northern  Great  Plains 
region.  This  applies  onlj  to  fall  plowed  land.  The  reason  Eorthisis 
obvious,  as  both  these  operations  may  work  against  the  conservation  of 
the  winter  precipitation  by  preventing  penetration  and  promoting 
run  off.  Rough  plowed  land  under  the  conditions  described  hold-  a 
large  portion  of  the  moisture  due  to  rain  or  melted  snow  and  gives  it 
;in  opportunity  to  soak  in  after  each  thaw.  Spring-plowed  fields  in 
the  intermountain  area  and  southern  Great  Plains  should  be  given  the 
treatment  previously  indicated  for  similar  fields  in  the  colder  por- 
tions of  the  ( ireat  Plain-. 

A  promising  method  of  securing  the  desired  seed  bed,  developed 
l>v  Dr.  W.  J.  Workman,  of  Ashland,  Kan-.,  has  been  found  to  give 
satisfactory  results  on  buffalo-grass  sod.  The  principal  difficulty  in 
the  growing  of  alfalfa  in  cultivated  row-  for  seed  is  the  weediness 
of  the  ground  during  the  firsl  season  after  seeding.  This  is  avoided 
by  the  utilization  of  sod  land.  A  L6-inch  sod  plow  is  used  to  cut  a 
furrow  -2\  inches  deep  through  the  sod,  a  stirring  plow  following 
immediately  in  the  furrow  left  by  the  breaking  plow  and  leaving  a 
furrow  about  s  inches  deep.  On  the  next  round  the  breaking  plow 
puts  the  strip  of  sod  in  the  bottom  of  the  deep  preceding  furrow. 
where  it  is  completely  covered  by  the  new  soil  turned  up  by  the  stir- 
ring plow.  The  harrow  i-  kept  at  work  to  smooth  and  firm  the 
ground  as  fast  as  it  is  turned,  and  the  alfalfa  is  seeded  with  the  grain 
drill  while  the  -oil  is  still  moist. 

THE  PREVENTION  OF  THE  DRIFTING  OF  SOIL. 

If  the  ground  is  so  sandy  as  to  be  in  danger  of  drifting  or  blow- 
ing during  high  winds,  it  is  the  best  practice  to  seed  alternate  rows 
of  oat-  or  barley  and  to  make  these  rows  run  at  right  angles  to  the 
direction  of  the  prevailing  wind-.  The  first  cultivation  of  the  alfalfa 
plants  will  destroy  this  grain  nurse  crop,  which  should  in  no  event 
he  left  long  enough  to  injure  the  young  alfalfa  plant-. 

Another  method  of  avoiding  the  danger  of  blowing  out  or  drifting 
in  a  sandy  -oil  i-  to  sow  the  alfalfa  with  a  walking  garden  drill 
between  corn  or  sorghum  row  -  after  the  last  cultivation.  This  method 
ha-  been  tried  with  success  under  irrigation  on  the  experiment  farm 
conducted  by  the  Office  of  Western  Agricultural  Extension  near 
Fallon,  Ne\.  In  attempting  to  use  the  method  under  dry-farming 
condition-  careful  attention  must  he  given  to  the  supply  of  moisture 
available  lor  both  plant-,  and  a-  it  ha-  not  yet  been  put  into  actual 
practice  in  the  -emiarid  sections  it  should  lir-t  he  tested  on  a  -mall 
scale. 

A  third  method  ha-  been  suggested  l>\  Dr.  11.  I>.  Shantz,  of  the 
Office  of  Alkali  and  Drought    Resistant    Plant    Breeding   [nvestiga 

[Clr.24] 


14  ALFALFA    IN    CULTIVATED    ROWS  FOR   SEED. 

tions,  Bureau  of  Plant  Industry,  which  may  prove  useful  when  sod 
laud  is  used.  This  method  consists  of  leaving  narrow  strips  of  virgin 
sod  a(  suitable  intervals  through  the  fields  at  right  angles  to  the  pre- 
vailing direction  of  the  most  destructive  winds. 

A  method  applicable  especially  to  old  fields  which  show  a  tendency 
to  blow  during  high  winds  has  been  suggested  by  Air.  X.  Schmitz,  of 
the  Office  of  Forage  Crop  Investigations,  Bureau  of  Plant  Industry. 
This  method  calls  for  the  seeding  of  the  alfalfa  in  shallow  listed 
furrows  running  at  right  angles  to  the  direction  of  the  prevailing 
heavy  winds.  It  is  necessary  that  these  furrows  be  shallow,  or  heavy 
rains  which  sometimes  occur  may  bury  the  seedling  plants.  If  the 
planting  does  not  take  place  at  the  time  of  listing  or  if  the  planting 
attachment  to  the  lister  can  not  be  adapted  to  this  work,  a  corn  drill 
or  check-row  planter  may  be  used  by  making  the  necessary  alterations 
in  the  plates,  as  suggested  on  page  15.  This  method  of  listing  may 
also  prove  efficient  in  catching  the  snow  during  the  winter  preceding 
the  planting.  Spring  harrowing  will  level  the  ridges  if  they  are  too 
high  at  planting  time. 

CHOICE  OF  SEED  FOR  CULTIVATION  IN  ROWS. 

Other  things  being  equal,  seed  from  plants  grown  without  irriga- 
tion should  be  used  in  preference  to  any  other.  The  relatively  small 
quantity  required  when  this  method  is  used  justifies  increased  pre- 
caution and  expense  to  obtain  the  best  seed  available.  Some  few 
strains  of  Turkestan  alfalfa  have  given  better  yields  of  hay  than  the 
ordinary  kind  under  semiarid  conditions.  However,  none  of  them 
have  shown  satisfactory  seed-producing  capacity.  Special  dry-land 
strains  of  alfalfa  that  have  been  developed  through  unconscious 
selection  in  some  of  the  older  dry-farming  centers  of  the  West  prac- 
tically always  exceed  in  seed  production  the  Turkestan  and  all  other 
forms  of  alfalfa  thus  far  introduced.  Whenever  these  kinds  can  be 
secured  they  should  be  preferred  by  the  farmer.  Seed  from  the  drier 
parts  of  western  Kansas  and  Nebraska,  from  the  dry  farms  of  Cache 
Valley,  and  from  the  Levan  Ridge  near  Xephi,  Utah,  will  probably. 
produce  the  most   satisfactory   results. 

METHOD   OF   SEEDING   IN   ROWS. 

Several  methods  have  been  used  in  experiments,  but  the  best  result- 
have  been  obtained  by  sowing  seed  in  rows  about  :'>  feet  apart.  The 
distance  between  rows  should  be  governed  by  the  moisture  supply  that 
can  lie  counted  on  and  by  the  width  of  the  machinery  available  for 
use  in  cultivating.  If  seeding  is  done  with  an  ordinary  grain  drill 
with  shoes  8  inches  apart,  the  stopping  up  <>f  1  out  of  every  ■>  holes 
will  make  I  he  rows  l<>  inches  apart.  If,  on  the  other  hand,  ;3  out  of 
[Cir.  :>4] 


\U  \l.i  UN   I  I  l.l  IV  \  i  ED    l.'"\\  S    FOB    S]  15 

every  I  boles  are  stopped  up,  the  rows  will  be  32  inches  apart.    The 
wider  distance  is  recommended,  especially  in  sections  where  the  rain 
fall  is  verj   scant. 

Ajiother  method  which  has  given  good  results,  especially  in  hay 
growing,  and  which  ma\  often  prove  useful  where  it  is  proposed  to 
use  the  same  field  for  both  hay  and  seed  production,  is  thai  of  sow- 
double  instead  of  single  row-.  This  can  be  accomplished  by 
leaving  2  hole-  open  and  stopping  up  3  or  I  hole-  aero--  the  drill. 
The  double  rows  will  then  he  8  inches  apart,  while  the  .-pace  left  for 
intertillage  will  lie  32  or  |o  inches  wide.  Experiments  with  this 
method  which  have  been  under  way  for  two  seasons  on  the  San 
Antonio  Experiment  Farm  of  the  Office  of  Western  A.gricultural 
Extension  indicate  that  this  method  will  he  useful  under  some  con- 
ditions. It  lias  al-o  been  used  with  success  under  Professor 
Wheeler's  direction  on  the  State  substation  farm  at  Highmore. 
S.  Dak. 

Any  good  garden  drill  will  give  satisfactory  results.  If  such  an 
implement  is  not  available  it  may  he  found  advisable  to  procure  one 
for  use  in  thi-  work. 

\n  ordinary  corn  drill  such  a-  i-  used  in  drilling  corn  in  listed 
furrows  can  lie  u-i'<\  by  babbitting  up  the  holes  in  the  corn  plate  and 
drilling  new  one-  of  proper  size  to  drop  about  15  alfalfa  seeds.  If 
a  blank  plate  is  at  hand,  holes  may  he  drilled  into  that  large  enough 
to  drop  from  1<)  to  20  seed-.  The  germination  value  of  the 
and  all  factor-  that  tend  to  lessen  the  ultimate  number  of  plants 
niu-t  he  considered  in  determining  how  thickly  to  seed.     The  holes 

should  lie  close  enough  to  drop  seeds  at   intervals  of  IV 8  to   12 

inches. 

Mr.  Lewis  Brott,  a  pioneer  dry-land  alfalfa  seed  producer  in 
western  Nebraska,  ha-  had  successful  results  by  using  an  onion  seed 
plate  in  a  corn  drill. 

RATE  OF   SEEDING  AND   THICKNESS   OF   STAND. 

In  mature  stands  of  alfalfa  in  cultivated  rows  the  plants  should 
averaj  I    1    foot  apart   in  the  row.    To  insure  this,  it   is  neces- 

sary that  the  plant-  be  much  thicker  at  first,  as  their  mortality  under 
i\v\  conditions  is  very  high.  Satisfactory  results  have  been  secured 
by  seeding  the  alfalfa  with  an  ordinary  grain  drill  so  set  that  it 
would  sow  12  pound-  of  seed  per  acre  with  all  the  hole-  in  operation. 
With  I  out  of  every  •">  hole-  -topped  up.  approximately  2jj  pounds 
if  seed  to  the  acre  will  he  -own. 

The  stand  in  a  cultivated  row  need  he  no  thicker  even  at  first  than 
that  of  the  row-  in  ordinary  drilled  held-,  though  the  row-  of  the 
latter  are  usually  only  about  s  inches  apart.     Where  the  conditions 

[Cir.24] 


16  ALFALFA  IN  CULTIVATED  ROWS  FOR  SEED. 

are  not  favorable,  it  is  usually  best  to  seed  more  thickly  at  first  than 
is  necessary  and  to  thin  out  the  plants  subsequently  to  the  desired 
stand.  As  much  as  7  pounds  of  seed  to  the  acre  have  been  sown  in 
36-inch  rows  without  producing  too  thick  a  stand  for  satisfactory 
results  during  the  first  season.  This  rate  of  seeding  is  equivalent 
to  30  pounds  per  acre  drilled  in  the  usual  way  under  conditions  of 
sufficient  moisture  with  the  rows  8  inches  apart. 

If  difficult}'  is  experienced  in  making  the  drill  feed  slowly  enough, 
it  may  be  overcome  for  the  most  part  by  mixing  corn  chop  with  the 
alfalfa  seed  or  by  reducing  the  feed  in  the  grain  drill  with  strips  of 
leather. 

Millet  or  other  seed  of  similar  size  may  be  rendered  ungerminable 
by  heating  thoroughly  in  an  oven  for  several  hours  and  then  mixed 
with  the  alfalfa  seed  to  aid  in  securing  any  desired  rate  of  seeding. 
Sawdust  and  dry  soil  are  also  frequently  used  for  this  purpose. 

It  is  a  very  good  plan  to  test  the  drill  first  on  bare  soil  with  the 
shoes  not  touching  the  ground.  In  this  way  it  is  possible  to  observe 
the  rate  at  which  the  seed  is  being  dropped,  and  thus  a  proper  regula- 
tion of  the  seeding  can  be  secured.  There  should  be  an  average  of 
from  I  to  10  plants  to  the  running  foot.  It  has  been  too  often  the 
case  that  the  stand  in  the  row  has  been  too  thick  for  the  best  develop- 
ment of  the  individual  plants.  In  such  instances  cross-harrowing 
after  a  majorit}'  of  the  plants  have  become  well  established  will  be 
found  to  be  very  effective  in  thinning  out  the  stand. 

SEEDING  IN  CHECK   ROWS   TO  PERMIT   CROSS-CULTIVATION. 

Limited  experiments  with  seeding  in  check  rows  indicate  that  with 
heavy  seed-producing  plants  of  satisfactory  character  very  good 
yields  of  seed  may  be  secured  with  hills  30  inches  apart  in  the  row. 
This  distance  permits  of  cross-cultivation,  hut  is  rather  narrow  for 
most  cultivating  machinery.  The  plants  being  thus  isolated  on  all 
sides,  the  production  of  a  maximum  seed  crop  is  possible.  Xo  prac- 
tical means  have  yet  been  devised  for  seeding  alfalfa  in  check  rows 
on  a  large  scale.  It  is  probable  that  an  ordinary  check-row  corn 
planter  can  lie  adapted  to  this  work.  It  would  he  necessary  to  bab- 
bitt up  the  holes  in  the  plate  and  then  rim  them  out  to  drop  10  to  20 
seeds  in  a  place.  The  surviving  plants  can  later  on  be  thinned  to  the 
best  plant  in  the  hill.  The  portion  of  the  field  shown  on  the  right  of 
the  picture  in  figure  2  is  sown  in  check  rows.  It  is  possible  that 
alfalfa  seeded  in  rows  with  a  wheat  drill  could  be  thinned  out  to 
practically  uniform  distance-  by  cross-cultivation  with  an  ordinary 
corn  plow  run  at  right  angles  to  the  rows.  The  plants,  with  (he  ex- 
ception of  a  few  midway  between  the  two  sets  of  shovels,  would  thus 

be  destroyed. 

[Cir.  24] 


\!  I  \i.l  \    l.\    (  ll.i  i\  \  i  ED    BOWS    FOB    SJ  1  7 

TIME   OF   SEEDING. 

Early  spring  seeding  will  usually  yield  the  besl  results,  as  more 
favorable  moisture  conditions  for  the  germination  and  growth  of  the 
young  plants  are  present  at  this  time.  However,  if  the  soil  can  be 
broughl  into  proper  condition  of  tilth  and  moisture  content,  seeding 
can  take  place  during  the  late  summer  if  the  danger  of  winterkilling 
is  ii< ii  too  great.  In  a  climate  of  moderate  severity  if  a  0-inch  growth 
is  made  during  the  fall  the  plants  will  probably  go  through  the 
winter  safely,  and  will  -tart  out  the  following  spring  in  much  better 
condition  to  compete  with  the  weed-  than  will  spring-seeded  plant-. 
In  semiarid  regions  it  i-  usually  impracticable,  however,  to  seed 
alfalfa  in  late  summer  or  early  fall  owing  to  the  lack  of  moisture 
necessary  to  insure  prompt  germination. 

In  the  Dakota-  and  .Montana.  June  seeding  will  probably  give  the 
hot  results.  If  seeding  i-  deferred  until  early  summer  and  the  soil 
is  harrowed  or  otherwise  treated  to  keep  it  in  proper  tilth,  nio.-t  of 
the  weed  -cimI-  near  the  surface  will  germinate.  The  las!  cultivation 
given  the  land  before  the  alfalfa  is  sown  kill-  this  young  growth,  thus 
greatly  reducing  the  trouble  with  weeds  during  the  firs!  season. 

TREATMENT  OF  THE  STAND  THE  FIRST  SEASON. 

The  well-settled  moist  seed  bed  necessarj  for  the  growth  of  alfalfa 
furnishes  ideal  conditions  for  the  rapid  development  of  weed-.  Sev- 
eral cultivations  are  necessary  to  hold  even  those  of  the  first  season  in 
check.  A  2-rovt  cultivator  provided  with  narrow  shovels  is  the  most 
practicable  machine  for  this  work.  Fender-,  or.  better,  a  bos  sled. 
should  he  provided  to  avoid  the  danger  of  covering  up  the  young 
alfalfa  plant-,  and  care  should  he  taken  to  ridge  up  the  rows  as  little 
as  possible,  a-  this  will  interfere  with  mowing  operation-.  After  the 
stand  has  become  firmly  established  ridging  can  he  readily  corrected 
by  cross-harrowing.  Mr.  Bartholomew  ha-  devised  a  harrow  id' 
adjustable  width  which  is  very  useful  both  in  controlling  weed-  and 
keeping  up  the  necessary  surface  mulch. 

The  -tand  may  he  much  thicker  during  the  first  season  than  in  sub- 
sequent seasons.  Some  "I'  the  plants  will  be  destroyed  by  cultivation, 
and  the  less  drought  resistant  and  less  hardy  plant-  will  he  killed  by 
the  dryness  of  the  summer  and  the  cold  of  the  first  winter.  Unless 
plant-  are  so  thick  a-  to  crowd  one  another  no  thinning  should  ho 
done  h\   cross-harrowing  while  the  plant-  are  -till  -mall. 

Experiments  in  eastern  Colorado,  eastern  Washington,  and  Cali 
fornia  indicate  that  under  \i-r\  < 1 1\  condition-  the  plant-  should  not 
he  clipped  the  firsl  season  if  they  are  to  make  their  greatest  indi- 
vidual development.  On  the  other  hand,  in  the  Willamette  Valley 
of  Oregon  it  ha- Ken  found  necessary  to  clip  during  the  first  season. 
In  nn\  event,  clipping,  if  undertaken  at  all.  should  he  with  the  sickle 

[fir.   24] 


18  ALFALFA   IN    CULTIVATED    ROWS    FOB    SEED. 

bar  of  the  mower  set  high,  and  probably  should  not  be  resorted  to 
unless  it  is  found  impossible  to  hold  the  weeds  in  check  by  the  ordi- 
nary cultivations.  As  there  is  still  some  uncertainty  regarding  clip- 
ping the  first  season,  it  is  suggested  that  farmers  leave  a  portion  of 
the  field  undipped  to  demonstrate  the  best  practice  under  various 
conditions.  Should  the  plants  begin  to  set  seed,  clipping  will  he 
advisable.  In  cases  where  it  is  practicable,  hand  weeding  or  hoeing 
maj'  be  used  to  supplement  horse  cultivation. 

TREATMENT    OF    THE    STAND    AFTER   THE    FIRST    SEASON. 

The  treatment  of  the  stand  during  subsequent  seasons  will  differ 
very  little  from  that  of  the  first  season.  The  plants  should  average 
not  more  than  four  to  the  foot.  In  the  spring  or  early  summer  of 
the  second  season,  if  the  natural  methods  of  thinning  out  have  not 
been  severe  enough  it  will  be  necessary  to  harrow  crosswise  lightly 
to  accomplish  a  further  reduction  in  thickness  of  stand.  It  may  also 
be  worth  while  to  go  over  the  rows  with  a  hoe  as  soon  as  the  plants 
commence  to  set  seed,  cutting  out  undesirable  individuals.  This 
operation  will  involve  considerable  time  and  expense.  However,  as 
there  is  such  great  variation  in  the  value  of  different  plants,  this 
procedure  may  be  justified  at  least  until  strains  of  known  high  value 
for  the  conditions  at  hand  have  been  selected  and  propagated  for 
use  on  a  field  scale. 

Row-sown  alfalfa  fields  that  have  not  been  properly  thinned  will 
not  give  maximum  seed  yields  on  account  of  the  various  injurious 
effects  of  crowding  which  have  already  been  discussed. 

If  it  is  impracticable  to  reduce  the  stand  by  hoeing  or  by  use  of 
the  ordinary  harrow  it  may  be  done  by  cross-disking  with  a  disk 
harrow.  The  disk's  should  be  so  adjusted  as  to  cut  out  the  proper 
number  of  plants,  which  will  depend,  of  course,  upon  their  original 
thickness  in  the  rows. 

THE  RIGHT  CROP  TO  LEAVE  FOR  SEED. 

Experiments  at  Stockton.  Ivans.,  show  clearly  that  at  that  place  no 
crop  later  than  the  second  will  yield  returns  that  will  he  at  all  satis- 
factory. Retarded  growth  during  the  dry  part  of  the  summer  defers 
ripening  until  so  late  in  the  season  that  cold  night-  prevent  the  ma- 
turing of  the  seed.  On  the  other  hand,  if  the  first  spring  growth  is 
devoted  to  seed  production  the  flowers  are  likely  to  become  overmature 
before  the  best  season  for  seed  development  arrives.  Frequently  also, 
largely  on  account  of  the  variation  in  location  of  the  zero  point  of 
growth"  in  the  different  individuals  composing  any  strain,  the  first 
spring  growth  matures  very  unevenly. 

°Brand,  Charles  .T.     Peruvian  Alfalfa:   A    \<w    Long-Season   Variety  for  the 
Southwest.     Bulletin  X".  ll*.  Bureau  of  Plant   [ndustry,  '  •  S.  Department  <>f 
Agriculture,  pp.  S  l  I.     L907. 
[Cir.  24] 


\i  i   \i  I  \    IN    I  ill  IV  \  I  ED    R0\*  S    FOB    SEED. 


19 


For  these  reasons  it  is  recommended,  especially  for  the  Great 
Plains  and  the  cooler  part-  of  the  intermountain  area,  that  the  first 
growth  of  the  second  and  subsequent  year-  be  clipped  so  early  that  the 
time  of  seed  setting  will  fall  in  midsummer  or  slightly  later,  when 
favorable  conditions  arc  likely  to  obtain. 

The  problem  as  to  what  crop  should  be  left  for  seed  under  the  vary- 
ing conditions  of  different  areas  has  not  yet  been  fully  worked  out. 
It  may  be  well  for  seed  growers  to  try  by  simple  experiments  along 
this  line  to  get  definite  information  on  this  point.  One  row  may  be 
given  an  early  clipping  and  then  left  to  go  to  seed;  another  a  later 
clipping,  while  still  another  may  be  left  for  seed  after  the  first  crop 
has  been  cut  for  hay.  and  so  on.  The- temperature  and  moisture  re- 
quirements \\  ill  largely  determine  the  best  practice  in  this  regard,  but 
the  necessary  presence  of  suitable  insects  must  not  be  overlooked. 

HARVESTING   THE   SEED   CROP. 

The  harvesting  of  alfalfa  seed  grown  in  cultivated  rows  does  not 
differ  materially  from  that  in  broadcasted  fields.  The  accompanying 
illustration  (fig.  3)  shows  a  bunching  device  used  by  Mr.  Lewi-  Brott, 
of  Sextorp,  Cheyenne  County.  Nebr.,  for  dropping  the  cut  plant-  in 


Pn 


m  ■.      g  machine  with  dropper  attachment  In  i  I  of  alfalfa  In  cul- 

tivated rows  in  western  Nebraska.     The  rows  in  this  case  arc  one-half  mile  1" 


windrow-  without  shattering  the  pods.  The  row-  in  this  instance 
are  36  niches  apart  and  weir  seeded  with  a  corn  drill  fitted  with  an 
onion  seed  plate  set  to  drop  at  l'1  inch  interval-.  With  the  row-  3 
feet  apart  a  mowing  machine  with  a  6  fool  cutter  bar  i-  necessary  if 

24] 


20  ALFALFA   IN    CULTIVATED   BOWS    loll    SKIP. 

two  rows  are  to  be  cut  in  each  swath.  This  arrangement  does  away 
with  the  necessity  of  having  an  extra  man  to  remove  the  newly  cut 
bunches  from  the  path  of  the  mower  at  the  next  round.  A  mower 
with  a  5- foot  cut  has  been  found  to  be  too  short  to  be  satisfactory  in 
cutting  two  rows  at  once. 

It  is  probable  that  a  center-cut  mower  with  one  horse  attached  at 
each  end  of  the  cutter  bar  will  prove  better  adapted  than  even  the 
6-foot  side-draft  machine. 

In  planning  to  sow  alfalfa  for  seed  in  cultivated  rows  the  farmer 
should  make  his  plans  from  the  very  beginning  with  a  view  to  using 
to  the  best  advantage  the  available  machinery.  In  adapting  the 
grain  drill  to  secure  the  proper  distance  between  rows,  the  mower 
with  which  the  cutting  is  to  be  done  must  be  kept  in  mind,  as  well 
as  the  cultivators  that  are  to  be  used  in  controlling  the  weeds  and 
keeping  up  the  dust  mulch. 

Thrashing  may  be  done  either  from  the  field  or  from  the  stack. 
The  latter  method  is  probably  the  better,  as  curing  in  the  stack  seems 
to  improve  the  quality  of  the  seed.  The  haste  necessary  in  order  to 
keep  the  machines  busy  when  thrashing  is  done  from  the  field  results 
in  considerable  waste.  Whichever  method  is  employed  in  handling 
the  seed  crop  it  is  necessary  that  a  tight-bottomed  rack  be  used  or 
there  will  be  much  loss  of  seed.  Such  a  bottom  can  be  secured  by 
the  use  of  matched  flooring  or  by  spreading  canvas  or  a  tarpaulin 
over  the  bottom  of  an  ordinary  open  rack. 

Thrashing  may  be  done  in  any  one  of  three  ways;  the  regular 
alfalfa  huller,  an  ordinary  grain  separator  supplied  with  a  hulling 
attachment,  or  a  grain  separator  fitted  out  with  alfalfa  sieves  may 
be  used.  The  last  has  been  found  to  give  very  satisfactory  results. 
Failure  to  appreciate  the  fact  that  the  ordinary  thrashing  machine 
can  be  adapted  to  the  thrashing  of  alfalfa  has  resulted  in  the  loss 
of  the  seed  crop  on  many  fields  in  sections  where  seed  production  is 
not  often  attempted  or,  if  attempted,  is  successful  only  in  abnormal 
years  or  where  it  is  carried  on  incidentally  to  other  farming  indus- 
tries. In  using  the  ordinary  thrasher  it  is  recommended  that  the 
concaves  be  inverted  in  addition  to  inserting  the  special  clover  or 
alfalfa  sieves. 

POSSIBILITIES  OF  SEED  PRODUCTION  IN  CULTIVATED   ROWS. 

Too  much  must  not  be  expected  from  the  method  of  growing 
alfalfa  described  in  these  pages.  There  are  large  areas  in  and  around 
the  regions  to  which  this  method  is  adapted  where  no  amount  of 
cultivation  and  isolation  of  the  plants  will  bring  success.  On  the 
other  hand,  there  are  thousands  of  acres  now  lying  idle  which  with 
intelligent  management  will  yield  profitable  crops.  Maximum  or 
[Cir.  24  j 


\[.l  \l  r\    IN    (  I'l.l  l\  Al  in    ROWS    FOB    SE]  I'. 


21 


"bumper"  crop-,  must  nut  be  expected  under  (lie  prevailing  con- 
ditions. 

The  results  obtained  in  the  experiments  thus  far  conducted  with 
this  method  indicate  that  it  gives  especial  promise  in  Utah,  in  east 

era  Colorado,  and  in  the  western  portions  of  Kan-as,  Nebraska,  and 

South  Dakota.  Yields  of  seed  at  the  rate  of  ■>  bushels  to  the  acre 
have  been  obtained.  The  possibilities  of  the  method  when  only  in- 
dividual plants  of  large  seeding  capacity  are  used  is  indicated  by  the 
fact  that  plants  removed  30  inches  each  way  from  other  plants  have 
given  yields  which  if  equaled  by  an  acre  of  such  plants  at  the  same 
distance  apart  would  rival  the  seed  yield  produced  under  the  most 
favorable  conditions  in  the  present  seed-growing  sections. 

The  method  is  a  comparatively  new  one  and  should  lie  tested  on 
it-  own  merits  in  each  area  or  even  in  each  community.  Where  rea- 
sonable doubt  as  to  it-  success  under  given  condition-  of  rainfall. 
etc.,  exists,  growers  should  at  first  devote  only  a  small  area,  say  2  to  5 
acre-,  to  row  cultivation,  increasing  the  size  of  the  held  if  the  results 
justify  it. 

Seed  production  under  the  best  conditions  is  somewhat  uncertain. 
The  certainty  of  profitable  yield-  of  hay  in  most  alfalfa-growing 
sections  deters  many  farmers  from  letting  their  fields  -land  for  seed. 
The  light  yield  of  hay  procurable  under  ordinary  conditions  in  the 
semiarid  regions  make-  the  growing  of  seed  a  more  promising  un- 
dertaking than  in  sections  when'  hay  production  is  very  profitable. 
It  is  probable  that  under  very  dry  conditions  the  yield  of  hay  in 
cultivated  rows  will  also  exceed  that  of  a  broadcasted  stand.  Com- 
plete data  are  not  yet  at  hand,  hut  calculated  yield-  per  acre  based  on 
the  weight  from  a  typical  rod  length  of  row  are  given  in  the  accom- 
panying table: 

Tabu  I. — Estimated  yield  of  hay  and  seed  t<>  tin  acre  when  «\u\U<\  \s  grown  in 

cultivated  rows. 


Variety. 


weight  of 
hay. 


Dry 

weight  of 
hay. 


Weight 
of Beed. 


Pounds. 

I»r\  land  at  fulfil  (Brott's) 

L) 

Turkestan  alfalfa  (S.  P.  I.  No  Lffi  J .  ill 


ruinate. 
1,154 


167 


The  yields  of  hay  given  in  this  table  are  from  one  cutting  obtained 
on  an  upland  field  near  Potter,  Nebr.,  sixteen  months  after  seeding. 
The  mean  annual  rainfall  at  Kimball,  the  nearest  point  for  which  pre 
cipitation  records  are  available,  is  about  II  inches,  [n  both  L905  and 
1906  this  mean  was  exceeded  considerably,  but  in  L907  the  total  was 
15  inches,  while  up  to  the  end  of  September,  L908,  tl  d  showed 

[Cir.24] 


22  ALFALFA    IX    CULTIVATED  ROWS  FOR  SEED. 

13.85  inches.  Mr.  Lewis  Brott,  on  whose  farm  this  experiment  is 
under  way,  secured  150  bushels  of  seed  from  a  thinly  sown,  broad- 
casted field  of  50  acres  in  190G.  This  yield  was  obtained  from  an 
old  stand. 

DEVELOPING   VALUABLE   STRAINS   FOR  SEED   PRODUCTION. 

Experiments  under  way  at  the  Arlington  Experimental  Farm,  near 
Washington,  D.  C,  at  Pullman,  in  the  eastern  part  of  the  State  of 
Washington,  and  elsewhere  tend  to  prove  that  heavy-seeding  propen- 
sity is  heritable  to  a  marked  degree.  In  consequence  of  this,  a  race  of 
unusual  excellence  could  readily  be  secured  by  propagation  of  the 
progeny  of  individuals  selected  on  this  basis." 

When  alfalfa  is  grown  in  rows  to  permit  of  intertillage,  it  is  much 
easier  to  make  selections  than  in  broadcasted  stands,  chiefly  hecause 
individuals  in  rows  have  better  opportunity  for  expression  of  their 
normal  character.  In  addition,  the  comparative  isolation  of  the 
plants  gives  readier  access  to  them. 

At  first  thought  it  might  appear  that  in  thinning  out  stands  of 
row-cultivated  alfalfa,  only  individuals  of  the  greatesl  seed-producing 
capacity  should  be  left.  A  second  thought  quickly  reveals  the  fallacy 
of  this  idea,  as  the  ultimate  purpose  of  all  alfalfa  growing  is  hay 
production.  Selection  based  on  seeding  habits  alone  will  develop 
this  side  of  the  plant  unduly  at  the  expense  of  its  forage-producing 
capacity.  The  highest  type  of  alfalfa  for  use  in  areas  where  seed 
production  is  the  primary  purpose  in  growing  the  crop  is  one  that 
combines  satisfactory  hay  and  seed  producing  quality  in  symmetrical 
proportions. 

It  is  recommended  that  the  selection  of  desirable  plants  commence 
as  soon  as  the  preliminaiy  seeding  has  developed  plants  large  enough 
to  show  their  value.  The  field  should  be  inspected  row  by  row.  and 
seed  of  the  selected  plants  should  lie  gathered  in  advance  of  the 
regular  harvest.  The  relatively  small  quantity  of  seed  secured  in  this 
way  should  be  sown  with  great  care  to  make  it  cover  the  greatest 
possible  area  of  ground.  The  plat  of  alfalfa  thus  secured  will  pro- 
duce seed  of  much  greater  value  than  that  obtained  from  unselected 
plants.  If  this  method  is  carried  out.  materially  increased  crops 
of  seed  may  be  secured  without  detracting  from  the  hay  value  of  the 
strain.  Indeed,  both  the  hay  and  the  seed  producing  capacity  may 
he  increased  by  the  process. 

Tf  it  i-  impracticable  to  secure  sufficient  seed  from  selected  plants 
for  all  of  the  new  seedings  that  one  desires  to  make,  the  selected  seed 


a  Some  progress  along  this  line  lias  already  been   made  by  Mr.  P.  K.  Blinn 
and  others.     Mr.  Blinn,  who  is  in  charge  of  the  State  substation  at  Rocky  Ford. 
Co]p.,  has  published  the  results  of  his  investigations  in  Bulletins  Nos.  121  and. 
128  of  the  Colorado  Agricultural  Experiment  station. 
[Cir.  24] 


ALFALFA   IN    CULTIVATED    BOWS    FOB    S]  23 

should  be  plained  separately,  and  thai  harvested  from  this  plat 
should  be  used  for  subsequent  seeding.  This  method  will  also  afford 
an  opportunity  for  demonstrating  the  relative  value  of  selected  as 
compared  with  unselected  stock. 

CONCLUSION. 

The  results  obtained  by  farmers  on  a  field  scale,  as  well  as  of  the 
experiments  thus  far  conducted,  indicate  that  the  growing  of  alfalfa 
in  cultivated  row-  for  seed  in  the  semiarid  regions  oiler-  every 
promise  of  success.  The  method  is  recommended  particularly  for 
those  sections  where  on  account  of  the  light  rainfall  but  one  crop,  or 
at  besl  two  crops,  of  alfalfa  hay  can  be  secured  in  each  season. 

V\!  to  the  problem  of  providing  and  maintaining  a   firm,  moist 

bed,  the  controlling  of  the  weed-  oiler-  the  greatest  difficulty. 

This  i-  especially  true  during  the  first  season,  when  their  rapid  growth 

makes  it  difficult  to  control  them  by  cultivation  owing  to  the  danger 

of  covering  the  small  alfalfa  plant-. 

It  i-  expected  that  the  machinery  now  in  use  in  mosl  communities 
can  he  adapted  to  i lie  growing  of  -eed  in  rows.  While  the  results 
indicate  that  the  row  method  of  culture  will  probably  become  an 
efficient  factor  in  the  development  of  the  semiarid  regions,  too  much 
must  not  lie  expected  of  it.  Those  undertaking  the  work  will  be 
pioneers.  I 'o  them  will  fall  the  task  of  developing  new  devices  and 
special  adaptations  of  the  implements  at  hand,  upon  which  will  de- 
pend in  a  large  measure  the  practical  success  of  the  method. 

The  alfalfa  plant  requires  hut  a  -mall  supply  of  moisture  when 
seed  setting  i-  going  on.  Heavy  -eed  crops  are  to  a  large  extent 
dependent  upon  the  prevalence  during  this  time  of  a  certain  amount 
of  dry  weather  and  heat.  In  many  part-  of  the  semiarid  regions  an 
unusually  favorable  combination  of  these  condition-  i>  present.  The 
power  to  regulate  by  surface  tillage  the  supply  of  -oil  moisture  makes 
the  method  of  growing  alfalfa  in  cultivated  rows  for  -eed  id'  especial 
promise  in  those  part-  of  the  Great  Plain-,  intermountain  area,  and 
other  sections  where  the  average  annual  rainfall  range-  from  14  to 
20  inches. 

Appro\  ed  : 

.1  \  \m  -  Wilson, 

•■///  '//'  .  [i/rii  ult in,  . 

Washington,  D.  ( '..  January  /  . 

[CIr.24] 

O 


UNIVERSITY  OF  FLORIDA 


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